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Discussion Starter · #1 ·
Building two cabinets with doors and adjustable shelves using 3/4" oak panels I will glue up. One is 78" H x 30" W x 12" D, the other is 42" H x 26" W x 12" D.
I know how to glue up the panels but, if gluing is so strong, is it advisable to glue the entire cabinet together without any fasteners?

Can make dados and rabbits where needed but will just using glue work? Can use biscuits or dowels but have heard, as far as gluing panels is concerned, that just glue is as strong as either biscuits or dowels.

Anyone try this? What has your experience been?
 

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It could or should work as long as you are not depending on any end grain joints.
If you study cases where there is a break along a joint, you will notice that the wood breaks on either side or both sides of the GLUE. This shows that the glue did its job and wood gave way. It happens. Now if there has been some metal fasteners, that little bit if extra holding power might be enough to prevent the break in the first place. No way of me knowing, I dont have access to a lab. Another thing that fasteners do is hold the joint tight until the glue cures. There are many conditions in woodworking where clamps are not suited for the task at hand or maybe just not practical.
So even though it should work, I personally wouldn't bet on it.
 

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Yes, end grain is an issue.....

When you build the case, how do you avoid end grain joints? Biscuits? Dowels? Dovetails in the casework?

None of the glue tests, to my knowledge deal with end gran to long grain. There is no doubt long grain to long grain is very strong, so I would look for a mechanical or interlocking type joint for the side panels to the top and bottom IF that applies in the design:



Or this for edge to edge for panel glue ups which provides a positive registration:

 

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When you build the case, how do you avoid end grain joints? Biscuits? Dowels? Dovetails in the casework?
Well. If you're using plywood you're always going to have 50% of an edge not be end grain, thanks to the ways the plies are oriented. Half the thickness is always going to be long grain
 

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I kinda figured you used rabits and dados. Yes, Ply is half end grain and half long grain at best, and that is if you used Apple Ply or real Baltic Birch (not the Home Depot knock-offs). However, have you considered that ends of ply tend to split off. The lesser the grade, the more the splitting off.

If I my goal was to NOT use fasteners, I have used long sliding dovetail joints for the shelves and other places where there would be 90* joints. Only have done it a few times, but never with plywood on the structure itself. Have done it with drawers though, using Baltic Birch and Apple Ply

Anyway, obviously it works for you but I still would never consider it.
 

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Discussion Starter · #13 · (Edited)
Thanks Ron J. The cabinet you made looks great (upright photo attached) and gave me some ideas. The trim, top and bottom, really adds some elegance.

The cabinet I am making is much like the one you made but will have full length doors and adjustable shelves. For strength the fixed bottom shelf that will be about 2" above the floor will be secured to the side panels with a dado and the top with a rabbet cut. The back will be 1/4" oak veneer plywood set in a rabbet cut and secured with glue and staples.

Sorry, thought I attached the photo but it didn't display.
 

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Discussion Starter · #14 ·
Thanks for that tip. Need to end glue a 3/4" x 4" x 8" oak board to make a 70" board 78" for a side panel. Plan to place this extended board in the middle of the panel so it has support on both sides.

Because it will be an end joint would it be necessary to rabbet the ends of both boards in this situation and glue them together? Thinking a biscuit in the joint may be all that is needed.
 

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No, it will not work without screws or penetrating joinery (dowels, Dominos, tongue and groove, etc) because rabbets and dados are end grain glue ups & end grain doesn't hold PVA type glue well.



So saying "no it will not work", I'll admit you can get away with a lot in ww'ing and perhaps you could glue up the cabinet as you propose, but as craftsman we strive to avoid the temptation to take the easy way out.

Screws are the most efficient way to build cabs, with or without glue. This can be screws through the sides or pocket screws. With plywood I generally do use glue.

Re: extending a panel, yes a rabbet will work for your situation, but biscuits, Dominos, splines or tongue and groove are also applicable.

BTW, BTDT and I've found I'm usually disappointed and/or feeling guilty for not having done it right. A lot of this starts with understanding joinery & construction methods.
 

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If you understand joinery it is absolutely possible, any time two or more boards meet it is called a joint, meaning they are fastened together.

The type of joint will provide the strength, glue will bond the parts together, the method used will determine the reliability.
 

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Discussion Starter · #18 ·
Dr. Robert, and anyone can answer - The PVA glue comment peaked my interest so had to look it up. If most white wood glue is PVA, what accounts for the various advertised holding bond? Surely Titebond 3 holds better than the Elmer's Glue school kids use.

Any comments on Titebond 1 (original), 2, and 3? Seems the newer stuff is more expensive. Are they really worth it?

While using a biscuit would be much easier, the rabbet I planned to use to join the 4" wide boards would be 3/8" D x 3" L. With those dimensions is it still called a rabbet or something else? My guess is three inches of long grain wood glued together with a PVA glue will hold, especially if that board is used to make up a panel with full length boards glued to it on either side.

If PVA glue does not hold end joints well, will clear Gorilla (non-foaming) Glue be advised? If so, any drawback to using Gorilla Glue for the entire project?

I agree with the saying you alluded to - There is never time to do a job right the first time but there is always time to do it over again.
That is why I am here asking questions of woodworkers who know more than I do.
 

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Just to be clear ......

Thanks for that tip. Need to end glue a 3/4" x 4" x 8" oak board to make a 70" board 78" for a side panel. Plan to place this extended board in the middle of the panel so it has support on both sides.

Because it will be an end joint would it be necessary to rabbet the ends of both boards in this situation and glue them together? Thinking a biscuit in the joint may be all that is needed.

You want to make a panel 78" long from several boards, but the center one needs to be "extended" by 8". It will have 78" long boards on either side for support. The question is ... How to do it?


Yes, you can rabbet the ends of the center joining piece, it won't hurt and may add some strength. However, by having complete 78" boards on either side, it would be all long grain edge glued together. and therefore plenty strong either way. :vs_cool:
 

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What about the back panel? Do you glue the back panel on? I use screws on back panels, not glue. Maybe I ought to rethink how I affix the backs.
I just glued mine. I'd be concerned if it was just 2 panels making a 90 degree angle, but when you add the top, bottom and in my case a shelf in the middle, it makes for a lot of joints to hold it in place.
 
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